1. Field of the Invention
The invention relates to prefabricated structural panels which can be rapidly assembled to form buildings of various types. Specifically the invention relates to structural panels which incorporate a lath connected to frame members.
2. Description of Related Art
There is a widespread need for a building system that uses common construction materials which are readily available throughout the world and can be quickly erected with a minimal labor force, is cost effective and whose construction is capable of withstanding extreme environments. Such a building system must be environmentally friendly while appearing to be similar to traditional buildings and structures and also must be constructed of materials which wisely utilize limited natural resources.
The demand for buildings, especially homes, in many third world countries is high. Additionally, current building methods many times are so slow, outdated and so labor intense that there is no way to satisfy the existing demand. While structures made from stone, block and concrete materials are time-tested and have proven their effectiveness worldwide, a change in building design must occur in order to keep up with this high demand. Portland cement, a common natural resource, has been used throughout the world for over two thousand years to produce concrete, mortar plaster and stucco. Steel has been used and relied upon since the early 1800s. Both portland cement and steel are cost effective and readily available from producers worldwide.
Therefore, a building utilizing a light gauge steel frame that can be covered with a cement exterior/interior coating and that would closely resemble currently existing buildings is desirable.
There are existing building systems that use light gauge laths, meshes, expanded metal or similar materials to build various types of stucco or plaster covered structures. All of these systems utilize discrete mechanical fasteners to attach the lath to the frame and must be used over a solid substrate such as plywood to provide adequate strength and to provide a material to which the fasteners can be attached. Once the lath is fastened, stucco or plaster, each of which is considered to be a cementitious coating, is applied in a series of layers over the substrate. The lath, once embedded in the cementitious coating, acts together with the coating to provide a structure having more strength using a design technique which offers a greater level of flexibility.
There are different types of existing commercial laths. The first type of lath is diamond mesh lath. It is manufactured out of thin sheets of metal that are slit with knives and stretched apart. The lath pattern resembles uniformly spaced small diamond shapes. The diamond mesh lath must be fastened to a substrate with nails or screws and must be used in conjunction with a solid surface because this diamond mesh lath is inherently flexible. The diamond shaped pattern allows the lath not only to be formed for contours but also provide a smooth surface desirable for ornamental work and smooth plaster finishes.
A second type of lath is a self-furring lath which may have a dimpled diamond or high ribbed surface that spaces the lath away from a mounting surface. These self-furring laths enable a structural coating to encapsulate the lath such that the lath is in the middle of the structural coating thereby providing greater strength. Self-furring laths, just as the diamond mesh lath, must be attached to a solid substrate such as plywood or water-resistant gypsum board using nails or screws.
A third type of lath is a lath having diamond patterns and having continuous flat ribs of steel which has a unique shape for added strength and support. This type of lath can be used over an open frame and does not require attachment to a solid substrate. However, this type of lath is limited for use on spans no greater than 16 inches and is not self-furring. In particular, one typical lath includes three 16-inch flat ribs spaced on 2-inch centers which run the continuous length of the lath. However, once again, these ribbed laths must be mechanically fastened to one another using discrete fasteners.
Finally, a flat-ribbed lath having a diamond shape in a reverse herringbone pattern may have V-shaped ribs that run the length of the lath. In one instance, ⅜-inch V-shaped ribs are spaced at 4½ inch intervals and provide structural support on open framed cavities having framing members spaced less than 16 inches apart. However, once again this type of lath must be mechanically fastened using discrete fasteners.
Each of these laths when used to cover a 2-foot by 8-foot area, requires between 36-45 fasteners. Not only do these fasteners add to the overall material costs, but also the time required to apply these fasteners increases the cost of labor and the overall time of construction.
Light gauge framing components made from coils of thin metal having various thicknesses and widths have existed for more than forty years. Such framing components typically consist of a web and a flange extending therefrom.
European Patent No. 159,764 issued to Illinois Tool Works on Oct. 30, 1985 shows a fastener for installing a sheet such as a lath spaced from a support. The lath described therein requires discrete mechanical fasteners.
Japanese Patent No. 03,290,555 issued to Adachi et al. on Dec. 20, 1991 shows a method for fixing an inner wall. This patent discloses a means of attaching a wood beam such as a ceiling or floor beam in a steel fitting means. There is neither a teaching nor a discussion of a lath.
Japanese Patent No. 03,286,029 issued to Misaka on Dec. 17, 1991 illustrates a steel underground wall and method of construction. This patent discloses a seismic reinforcement using a steel grid composed of beams, and neither teaches nor suggests the use of a lath.
European Patent No. 434869 issued to International Building Systems, Inc. on Dec. 15, 1993 illustrates a steel stud and precast panel which requires a fastening means before the introduction of concrete over a steel stud.
Japanese Patent No. 06,158,858 issued to Harino et al. on Jun. 7, 1994 illustrates a form for concrete foundation and describes a means of pouring concrete into a panel. This patent neither teaches nor discusses the use of a lath.
Japanese Patent No. 08,270,142 issued to Miyata on Oct. 15, 1996 illustrates a steel stud for a partition wall used in a coupling system for holding fireproof boards. There is neither a teaching nor a discussion of the use of a lath.
Japanese Patent No. 09,279,806 issued to Hosoda on Oct. 28, 1997 discloses a method for fixing a rib lath utilizing a means for fastening a lath including screw attachments to pierce through the lath at recess points.
Japanese Patent No. 10,161,189 issued to Hosoda on Jun. 23, 1998 illustrates a ribbed lath used as a form. This patent neither teaches a self-setting lath system nor suggests that the lath be applied to a stud.
Japanese Patent No. 10,237,994 issued to Shiozo et al. on Sep. 8, 1998 discloses a concrete panel made up of a lath and steel studs and a method utilizing heat to attach the lath to the steel studs.
A design for applying a lath to a frame is desired which requires no discrete fasteners for permanent connection and requires no solid substrates upon which to secure the lath.